The invention relates to eye goggles, in particular eye goggles as used for swimming.
Swimming goggles have been used for many years and, in general, comprise a pair of separate eyepieces interconnected at adjacent inner ends thereof by a nosepiece, and at oppositely located outer ends by a head strap adapted to pass around the head to secure the goggles to the face. Such goggles can be classified into two main types, namely goggles with essentially rigid nosepieces, and goggles with flexible nosepieces. Goggles with rigid nosepieces are usually more stable when fitted on the face, and thus do not easily become displaced and leak. Also, such goggles can be retained on the head with a relatively light head strap tension and they often more comfortable to wear than the other types of goggles. However, for some individuals, goggles with rigid nosepieces are awkward to fit as the nosepiece does not provide a wide range of adjustment of spacing between the eyepieces, which spacing is usually termed interocular separation or spacing. Thus, persons with eyes which are closer together or much wider apart than average can have difficulty in fitting goggles with rigid nosepieces which provide correctly spaced eyepieces with a secure and comfortable fit.
In contrast, goggles with flexible nosepieces are usually easy to adjust for a wide range of interocular spacing, but tend to be unstable when fitted on the face, and consequently require relatively high head strap tension to maintain a secure sealing fit. High head strap tension causes discomfort after a short while, and consequently such goggles are appropriate for short races, but tend to be uncomfortable for relatively long periods of wear.
There is also a third type of goggles comprising a one-piece goggles frame which has opposite ends interconnected by a head strap for securing to the head. The frame has a pair of eyepiece openings to receive respective eyepieces, the eyepieces being adjustable with respect to the eyepiece openings in the frame to accommodate spacing between the eyes of the person. An example of such goggles is found in U.S. Pat. No. 5,093,940 (Nishiyama). While this patent shows a means to easily adjust interocular spacing, the means of adjustment relies on friction to hold the eyepieces at the required interocular spacing. It has been found that the friction is sometimes insufficient to maintain the desired spacing of the eyepieces, causing the spacing between the eyepieces to inadvertently change, and thus such goggles often require frequent adjustment to maintain comfort and fit. In addition, the frame of Nishiyama is relatively flexible, and this also contributes to difficulty in adjusting the spacing of the eyepieces.
For persons requiring corrective lenses, that is refractive lenses, it is important that optical or ocular axes of the lenses coincide as closely as possible with the optical axes of the eyes. For such persons, accurate adjustment and maintenance of the interocular spacing of the eyepieces is important, as well as correct alignment of the eyepiece with respect to the eye. Consequently, when corrective lenses are used in goggles having a flexible nosepiece, difficulty can be experienced in positioning and maintained the eyepieces accurately with respect to the eyes to obtain adequate vision. Similarly, for goggles with essentially rigid nosepieces, adjustment of interocular spacing is also limited, and thus fitting corrective lenses to such goggles can be costly as spacing between the eyepieces must be individually adjusted to accommodate the person's eye spacing. For the third type of goggles exemplified by the above Nishiyama patent, while such structure permits easy adjustment of interocular spacing of the eyepieces, the spacing adjustment is easily lost and sometimes an eyepiece can rotate with respect to the frame, and thus frequent readjustment of the goggles would be necessary to attain satisfactory alignment of the optical axes.